I've got adjustable drop links, but still suspect that the sway is in part or wholly to blame. In my mind, the only way the driver side drop link should be angled like that is if I came into my driveway at 90mph, which I dont remember doing.. Its as if the whole sway bar is nearly 1" over to the passenger side, if that makes sense..

I noticed when I dropped the passenger rear to compensate the height difference, it slightly dropped the driver rear height also.

I'm thinking it's headed back to the shop..

 

sounds like your coil overs aren't seated evenly in the suspension carriers.

 

I've seen this on a few TT's.

 

Hello all..
I'm resurrecting this post one last time before I take the car into the frame shop to fork out some big bucks to see if it's not straight.. We've taken the rear back off and re-aligned again and same result, the passenger side is much higher than the driver (by 1/2"). This is with both sides height set relatively to the same thread left and right..

The car pulls to the right now, even after the alignment. Needless to say it's driving me crazy and I'm not really driving the car until I get it right. I'm up for any suggestions on what to look for before taking it in to check the frame. It just doesnt make sense to me that it was level with the factory shocks and not now after the install. I really dont think the frame is bent, but running out of viable options to check.

It's a 99 C4 if that rings any bells

All the best,
rb

 

when I had my pss9's installed my drivers side was 1/2" lower... we just dropped the pas. side to match... no problem doing so... maybe yours are not installed correctly or maybe you have 1 thats defective? something dont sound right

 

Thanks again boca,
I tried that also and was able to get it almost level. the thing that scared me when I did was the amount I had to spin the passenger rear down to get it 1/2" lower. It leaves one sides height adjustment spooled nearly all the way down while the driver side is moderate. This cant make for even rebound rates.. When I drove the car like this around the block it felt pretty darn unpredictable and unnerving so I reset it and re-aligned

I guess my question is, do you have one side with couple inches of thread left (drivers side) and the other (passenger) set nearly at the bottom?

It seems like this same problem has happened at least to a handful of people out there with tt's and C4's, seemingly always the driver side is lower.. There has to be something to it..

btw, boca - your car looks great
best,
rb

 

First of all, corner balance is BS unless driver weighs only 100 pounds (most racers do). With a driver at about 180 pounds and over, sitting in the car, good corner balance on our cars cannot be obtained! Also, corner balancing is useful for the track (light driver – load not changing) and useless on the street because as soon as you change one variable; such as offer a lift home to a fat blond chick you’ve just picked up at the bar, corner balance goes out the window. If you really must do it, corner balance the car with no driver. However, when you do that, our cars will corner balance so that the passenger side will be higher at about 10-15mm. It’s just the way it is due to asymmetrically arranged components in the car. Conversely, the rule according to the Porsche workshop manual is that the load across the wheels (diagonally) must not exceed 20kg. That is the only prerequisite they state. Nevertheless, this problem occurs to people who fit coilovers and are talked into corner balancing. The result is wonky ride height. For the track that really doesn’t matter but I really don’t want my car visibly sloping downwards to the left side when viewed from the rear! If you on the other hand, consider the fact that our car’s from the factory are non ride-height adjustable and come set equally all way around, just duplicate that with coilovers and you can’t be far from the correct setting. I have left my driver’s side 3mm higher, as per suggestion by my tuner, (that’s how much the car dips when I sit in) so when I am in the car alone the ride height drops to perfectly equal all way round – I weigh 195 pounds. I’ve checked the corner balance this way and load across the diagonal wheels is 17kg (3kg within the tolerance set by Porsche). Good enough for me.

 

Have you put all 4 tires on a drive-on lift and checked the compressed height of the spring package? When I had all ride heights nearly equal across from left to right, front and rear (being measured at the correct places) I found compressed spring pkg on left to be 5mm shorter and it caused my car to list to port by 5mm.

 

corner balancing ruined my handling.

 

How is that possible?

 

Because to corner balance car for the road - is stupid. Corner balancing is done for the track on race cars. Again, there are a lot of asymmetrically arranged components in our road version of the car you won’t find in any serious race car. With a non-professional (“fat”) driver weighing over 180 pounds you simply can’t corner balance our road version of the car effectively. As soon as you sit in the car, that side will drop 3-8mm depending on your weight. It will then be impossible to maintain less than 20kg Porsche rule across the diagonal axis. Porsche has build near enough equal ride-height across all 4 corners into the OEM non adjustable suspension. Therefore the OEM properties of the coils are different left to right by design in order to achieve this - left side is firmer. That’s how 911 Turbo left the factory (non-corner balanced) if you like. With coilovers we immediately run into desire for corner balancing. However when we do it car is of unequal ride-height - higher on the right side. So, don’t do it. Just set your car the way it left the factory - equal ride-height all four corners - and you can't go wrong.

 

I've got a Boxster S with JRZ coilovers and had a bunch of trouble setting ride height. Even with lots of adjustments I couldn't quite get it leveled out perfectly, still off 5-10 mm from corner to corner. I'm measuring from the ground through the center of the wheel to the fender, but I've also used lower suspension points as the measurement reference with the same kind of results. Coilover spring perch heights are also set precisely with digital calipers.

Recently I purchased a 996 C4S with TechArt coilovers and when setting the ride height ran into the exact same problem - I could not get the ride heights perfect. Who really cares about ride height any way, as long as it's close? Ultimately the performance of the car really depends on the corner weights. I finally gave up on trying to set my coilovers based on ride height and instead switched over to corner weighing to get very precise setups. I couldn't be happier!

Here's my C4S in the garage on the scales. Vinyl tiles are used to level the car as verified with a water level.



Here's the final result with 210 lbs in the driver's seat and 1/2 tank of gas:



Sure it won't be perfect when some fat chick is in the passenger seat, but hopefully I'm just driving her home. When I'm hitting it hard in the twisties the car will be balanced. Some of you guys seem to think that you can't perfectly corner balance a Porsche. You can, but understand that you can't change the total weight front to rear or left to right with just coilovers, this is basic corner balancing 101. You focus on the cross weights and try to get those even. You say Porsche specs no more than 20 kg difference in cross weight. As you see from my scales I've got mine down to about a 2 kg difference. It could have been ZERO if I had spent more time on it. Where you are at with just winging the coilover setup based on ride height is anyone's guess.

To the original poster - I would corner balance the car and don't worry about 12 mm in delta from side to side. As long as the tire contact patches are seeing a balanced weight you're good to go.

 

You are lucky. 2 points thought. First it isn’t a turbo and second if Porsche specs 20kg I don't believe you can ever tell the difference on your typical road (twisties) with some pot holes thrown in. There will be no difference between 2kg and 20kg or anything in-between as long as you are not over on the street. On track that's a different story. But well done for getting it so near. Ps. How long did it take you to get there? 8 hours in labour?

 

>First it isn’t a turbo

Should not matter. The weight in the rear will be higher, but an even cross weight can still be obtained. Same is true whether the driver is 100 lbs or 200 lbs.... Anyone with a turbo and coilovers in NorCal want to test this? I'll corner balance your car for free just to prove the point.


>There will be no difference between 2kg and 20kg or anything in-between as long as you are not over on the street.

You're probably right, depending on how hard you're pushing it on the street. There are obviously limits to what is reasonable in public settings. The main thing this helped me to do is avoid the problem of trying to adjust to some fender height as the only measuring tool. As with the original poster, I was finding that I was setting my shocks different 25 mm side to side to try to even out the ride height. It was just crazy that I would have the spring perches set sooooo differently just to try to even out the fender gap. Clearly my measurement reference was wrong. As you said, at least you could go to the same setting on each side and be where you'd be at if you didn't have adjustable coilovers! With the scales I can take it one step further and set the coilovers based on an accurate and repeatable measure.


>How long did it take you to get there? 8 hours in labour?

It took me a couple hours to start with just to raise up every corner and adjust my coilovers back to even side to side and un-do all of the screwing around I had done before when just trying to adjust for the ride height alone. Once I got things back to even it took me about two hours to jack the car up and get it on the scales (ramps would have helped obviously) and to do three adjustments to get it to 50%. Future work will be even faster. Labor was free. The scales were not free, but only $880 shipped. I have three cars with height adjustable suspensions and I like to play with them, so it made sense to me to have my own scales. I do my own alignments too....

 

Well done mate. Thumbs up. Might have to take you up on the offer and visit for you to corner balance my car. Only joking, I think ferrying my car by boat to the States would kill the deal. ;-).